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Open access

Jakub Szałatkiewicz, Roman Szewczyk, Mateusz Kalinowski, Juhani Kataja, Peter Råback, Juha Ruokolainen and Maciej Kachniarz

Abstract

Microwave devices are widely used in the industry and in the specialized laboratory analyses. Development of such devices requires the possibility of modeling of microwave energy distribution in the specific resonant chambers. Until now, such modeling was possible only with the use of commercial software or was limited to specific cases. The paper presents an open-source module for ELMER software for solving timeharmonic Maxwell’s equations, allowing modeling of microwave waveguide lines. Three test cases of different resonant chambers are investigated at 2.45 GHz frequency. Modeling results obtained from the open-source ELMER Vectorial Helmholtz module show that the application of this software can be effective in R&D works, enabling high-tech small and medium enterprises involvement in advanced microwave technology.

Open access

Michał Nowicki, Maciej Kachniarz and Roman Szewczyk

Abstract

The paper presents a special measurement system for investigation of temperature influence on the indication of commercially available sensors of the magnetic field. Utilizing the developed system, several magnetoresistive and Hall-effect sensors were investigated within the temperature range from −30°C to 70°C. The obtained results indicate that sensitivity of most of the investigated sensors is unaffected, except the basic magnetoresistive device. However, Hall-effect sensors exhibit considerable temperature drift, regardless of the manufacturer.

Open access

Ruslan Sobolevskyi, Igor Korobiichuk, Michał Nowicki, Roman Szewczyk and Vladimir Shlapak

Abstract

The regularities of the changes of horizontal and sub-horizontal systems of cracks at different locations of Holovyne labradorite deposits are studied. The trend for stress to increase has been established in the quarry LLS “Optima” for Holovyne labradorite deposits in Volodar-Volynsk district, Zhytomyr region at the deepening of excavation. The duration of the working cycle of borehole drilling in a solid and cracked massif is calculated using a new method. The calendar planning method of mining is developed taking into account the dependence of drilling efficiency on horizontal and sub-horizontal systems of cracks.

Open access

Peter Švec, Roman Szewczyk, Jacek Salach, Dorota Jackiewicz, Peter Šlvec, Adam Bieńkowski and Jozef Hoško

Abstract

Magnetoelastic properties of Fe6iCoigSÍ5Bi5 alloy after thermomagnetic treatment were tested for both compressive and tensile stresses, what is significant novelty. Results of presented investigation opens new ways of modelling the magnetoelastic effects in amorphous systems tailored by thermomagnetic treatment.

Open access

Hanna Kwaśna, Lucyna Walkowiak, Piotr Łakomy, Jolanta Behnke-Borowczyk, Roman Gornowicz, Artur Mikiciński, Stanisław Gałązka and Wojciech Szewczyk

Abstract

Effects of different pre-planting soil preparations and post-harvest wood debris applications in a clear-cut Scots pine plantation, on the abundance, diversity, and activity of culturable microorganisms were investigated. The investigation was done 9 years after the re-plantings had been done. This formed part of an investigation of silvicultural practices for conservation and the biological control of Armillaria and Heterobasidion in northern temperate forests (Poland). The treatments being compared, were expected to have altered the soil’s physical and chemical properties, and consequently, its biological properties. Only soft-rot microfungi from the Ascomycota and Zygomycota were detected in the soil. Fungi, including those antagonistic to Armillaria and Heterobasidion, were more abundant after shallow ploughing than after deep ploughing or ridging, and where chipped rather than coarse wood debris was left on the soil surface or incorporated. Scots pine trees had the most biomass and the least mortality after ridging and leaving coarse wood debris on the surface (associated with only a relatively moderate abundance of fungi).